1. Field of the Invention
The present invention relates to a printer device which causes to fly or travel ink containing charged pigment particles through an electric field.
2. Conventional Art
The following ink discharge methods for an ink jet recording device which forms pixels on a recording medium by blowing liquid ink drops were known:
(1) an electro and thermal conversion method in which ink is discharged from a nozzle by making use of pressure of bubbles caused by heating the ink through a heating element. PA1 (2) an electro static method in which insulative ink solvent is polarized by an electric field or conductive ink solvent is electro-statically pulled out. JP-B-56-9429 discloses an ink jet recording device using the electro and thermal conversion method, and JP-A-56-4467 and JP-A-8-174815 disclose ink jet recording devices using the electro static method. PA1 (1) diameter of a print dot is about 1 .mu.m.about.10 .mu.m; PA1 (2) a pulse electric field applying means is provided between the respective discharge electrodes and the opposing electrode and the pulse electric field applying means further includes a control means which varies the diameter of the print dot by varying a pulse voltage and pulse width; PA1 (3) partition members for guiding ink stream are provided at both sides of the respective discharge electrodes, and the top ends of the partition members (the top ends from which the liquid ink drops flow out) are restricted; and PA1 (4) the top ends of the respective discharge electrodes are restricted in a triangle shape in order to concentrate electric field at the top ends of the respective discharge electrodes, the restricted top end angle is selected less than 90.degree., and preferably to be 30.degree..about.70.degree.. PA1 (1) charged amount per unit mass of the charged pigment particles is 10.about.200 mC/g and, the charged pigment having particle radius of 0.1.about.5 .mu.m is contained in 2.about.10 vol %; and PA1 (2) at least two kinds of charged pigment particles having different charged amount per unit mass and different particle diameter are included.
However, the ink jet recording device as mentioned above using the electro and thermal conversion method is not suitable for a gradation recording, because the ink discharge amount does not depend on the applied voltage. Further, although it is necessary to provide respective heating elements for respective nozzles, it is difficult to arrange the nozzles in high density. Moreover, if the diameter of the nozzle aperture is reduced in order to improve resolution, the nozzle aperture tends to clog due to solidification of the ink which reduces discharge stability of the ink.
On the other hand, in the ink jet recording device as mentioned above using the electro static method, since the ink discharge amount sensitively responds to a variation of electric field near the top of the respective nozzles, the ink discharge amount tends to unstabilize. Further, when a conductive ink is used, it is necessary to avoid a mutual action between flying liquid ink drops by limiting discharge frequency of the ink from the nozzles which reduces recording speed.